Discussion Overview
The discussion centers around the solubility of Cu(OH)2 in an aqueous CuSO4 solution, particularly at a low pH of around 4. Participants explore why Cu(OH)2 does not precipitate despite the presence of hydroxide ions and consider the role of complexation in the solution.
Discussion Character
- Exploratory, Technical explanation, Debate/contested
Main Points Raised
- One participant notes that the pH of CuSO4 solution indicates a higher concentration of H+ ions compared to OH- ions, raising the question of where the OH- ions are located.
- Another participant suggests that the solution may contain copper complexes with OH- groups, mentioning several possible soluble complexes such as CuOH+, Cu2(OH)22+, and Cu(OH)42-.
- A later reply questions the presence of Cu(OH)42-, arguing that if it were present, Cu(OH)2 would be soluble in water or alkaline solutions.
- One participant points out that the solubility of Cu(OH)2 depends on the relative values of the stability constant and solubility product, referencing an equilibria database for this information.
- Another participant expresses uncertainty about finding the stability constants but mentions that Cu(OH)42- forms only at very high pH, implying a low stability constant.
Areas of Agreement / Disagreement
Participants express differing views on the presence and role of various copper hydroxide complexes, indicating that multiple competing perspectives remain without a clear consensus.
Contextual Notes
Participants acknowledge limitations in their understanding of stability constants and solubility products, which may affect the discussion's conclusions.